ported configureByResource from logback

core/play-logback/src/main/scala/play/api/libs/logback/LogbackLoggerConfigurator.scala

@@ -9,9 +9,11 @@ import java.net.URI
 import java.net.URL
 
 import ch.qos.logback.classic._
+import ch.qos.logback.classic.joran.JoranConfigurator
 import ch.qos.logback.classic.jul.LevelChangePropagator
 import ch.qos.logback.classic.util.ContextInitializer
 import ch.qos.logback.core.util._
+import ch.qos.logback.core.LogbackException
 import org.slf4j.bridge._
 import org.slf4j.ILoggerFactory
 import org.slf4j.LoggerFactory
@@ -122,8 +124,7 @@ class LogbackLoggerConfigurator extends LoggerConfigurator {
 
       config match {
         case Some(url) =>
-          val initializer = new ContextInitializer(ctx)
-          initializer.configureByResource(url)
+          configureByResource(ctx, url)
         case None =>
           System.err.println("Could not detect a logback configuration file, not configuring logback")
       }
@@ -132,6 +133,17 @@ class LogbackLoggerConfigurator extends LoggerConfigurator {
     }
   }
 
+  private def configureByResource(ctx: LoggerContext, url: URL): Unit = {
+    val urlString = url.toString
+    if (urlString.endsWith("xml")) {
+      val configurator = new JoranConfigurator()
+      configurator.setContext(ctx)
+      configurator.doConfigure(url)
+    } else {
+      throw new LogbackException("Unexpected filename extension of file [" + url + "]. Should be .xml")
+    }
+  }
+
   /**
    * Shutdown the logger infrastructure.
    */